1. Field of Invention
The present application relates to light reflecting polymeric compositions.
2. Description of Related Art
Most light sources emit light in the visible range of the electromagnetic spectrum (i.e., wavelengths from about 400 nm to 700 nm) in all directions, which necessitates the use of one or more reflectors to concentrate the light and direct it in the desired location. Studies have shown that light, which travels in a straight line, typically reflects or “bounces” off the surface of one or more reflectors in a lighting fixture an average of five times before it is properly directed in the desired location. For example, if the reflector material reflects 90% of the light, then 90% of the emitted light is reflected on the first reflection or “bounce” and 10% of the light is absorbed by the reflector material. On the second “bounce”, 90% of the light reflected from the first bounce is reflected a second time, and 10% of that reflected light is then absorbed by the reflector material. After five “bounces”, only about 59% of the light originally emitted from the light source is available to reach the targeted area (90.000%×90.000%×90.000%×90.000%×90.000%=59.049%).
For many years, efforts have been made to develop highly reflective polymeric materials because relatively small improvements in the percent reflectivity of polymeric compositions can have a substantial effect on the amount of light directed in the desired location and the amount of energy needed to produce the required lighting. Using the same example as above, if the percent reflectivity of the reflector material can be increased by 8.000% (i.e., to 98.000%), then about 90.392% of the light originally emitted from the light source is available to reach the targeted area (98.000%×98.000%×98.000%×98.000%×98.000%=90.392%). Thus, a mere 8% improvement in the reflectivity of the material used to fabricate the reflectors in a lighting fixture can result in a 30% increase in lighting efficiency.